bpf: add __must_check attributes to refcount manipulating helpers

Helpers like bpf_prog_add(), bpf_prog_inc(), bpf_map_inc() can fail
with an error, so make sure the caller properly checks their return
value and not just ignores it, which could worst-case lead to use
after free.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Daniel Borkmann 2016-11-19 01:45:03 +01:00 committed by David S. Miller
parent a055c19be9
commit 6d67942dd0

View File

@ -233,14 +233,14 @@ void bpf_register_map_type(struct bpf_map_type_list *tl);
struct bpf_prog *bpf_prog_get(u32 ufd);
struct bpf_prog *bpf_prog_get_type(u32 ufd, enum bpf_prog_type type);
struct bpf_prog *bpf_prog_add(struct bpf_prog *prog, int i);
struct bpf_prog * __must_check bpf_prog_add(struct bpf_prog *prog, int i);
void bpf_prog_sub(struct bpf_prog *prog, int i);
struct bpf_prog *bpf_prog_inc(struct bpf_prog *prog);
struct bpf_prog * __must_check bpf_prog_inc(struct bpf_prog *prog);
void bpf_prog_put(struct bpf_prog *prog);
struct bpf_map *bpf_map_get_with_uref(u32 ufd);
struct bpf_map *__bpf_map_get(struct fd f);
struct bpf_map *bpf_map_inc(struct bpf_map *map, bool uref);
struct bpf_map * __must_check bpf_map_inc(struct bpf_map *map, bool uref);
void bpf_map_put_with_uref(struct bpf_map *map);
void bpf_map_put(struct bpf_map *map);
int bpf_map_precharge_memlock(u32 pages);
@ -299,7 +299,8 @@ static inline struct bpf_prog *bpf_prog_get_type(u32 ufd,
{
return ERR_PTR(-EOPNOTSUPP);
}
static inline struct bpf_prog *bpf_prog_add(struct bpf_prog *prog, int i)
static inline struct bpf_prog * __must_check bpf_prog_add(struct bpf_prog *prog,
int i)
{
return ERR_PTR(-EOPNOTSUPP);
}
@ -311,7 +312,8 @@ static inline void bpf_prog_sub(struct bpf_prog *prog, int i)
static inline void bpf_prog_put(struct bpf_prog *prog)
{
}
static inline struct bpf_prog *bpf_prog_inc(struct bpf_prog *prog)
static inline struct bpf_prog * __must_check bpf_prog_inc(struct bpf_prog *prog)
{
return ERR_PTR(-EOPNOTSUPP);
}